Fixing iframe.contentWindow.postMessage passing incorrect data

tools/dom/src/dart2js_DOMImplementation.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of html;
 
 // TODO(vsm): Unify with Dartium version.
 class _DOMWindowCrossFrame implements WindowBase {
   // Private window.  Note, this is a window in another frame, so it
   // cannot be typed as "Window" as its prototype is not patched
@@ skipping 14 matching lines @@
 
   WindowBase get parent => _createSafe(JS('WindowBase', '#.parent', _window));
 
   WindowBase get top => _createSafe(JS('WindowBase', '#.top', _window));
 
   // Methods.
   void close() => JS('void', '#.close()', _window);
 
   void postMessage(var message, String targetOrigin, [List messagePorts = null]) {
     if (messagePorts == null) {
-      JS('void', '#.postMessage(#,#)', _window, message, targetOrigin);
+      JS('void', '#.postMessage(#,#)', _window,
+          convertDartToNative_SerializedScriptValue(message), targetOrigin);
     } else {
-      JS('void', '#.postMessage(#,#,#)', _window, message, targetOrigin, messagePorts);
+      JS('void', '#.postMessage(#,#,#)', _window,
+          convertDartToNative_SerializedScriptValue(message), targetOrigin,
+          messagePorts);
     }
   }
 
   // Implementation support.
   _DOMWindowCrossFrame(this._window);
 
   static WindowBase _createSafe(w) {
     if (identical(w, window)) {
       return w;
     } else {
@@ skipping 59 matching lines @@
 
   static HistoryBase _createSafe(h) {
     if (identical(h, window.history)) {
       return h;
     } else {
       // TODO(vsm): Cache or implement equality.
       return new _HistoryCrossFrame(h);
     }
   }
 }